Because it was Thursday, it was also Xursday, which is a kind of weekly holiday for the Destiny enthusiast. I mention this because it's something that you either know in your very mitochondria or it's something that you have no awareness of whatsoever. In any case, there is a drop currency like you have in games of this sort called a Strange Coin, and this Xur fellow is functionally a mercenary Santa Claus who accepts these coins and naught else. And until now, nobody knew why.
